How to Restore a Lawn After a Salt Water Flood

Lawns can be hard hit by salt water floods.

The health of your grass may be the least of your worries after your property is hit by coastal flooding. The sooner you can mobilize to save your lawn, however, the less time and money you'll need to spend in the future. Not surprisingly, salt water has a drying effect on plants, virtually sucking the water they need right out of their root systems. Grass is no exception. Once the flood is over, take steps to remove the damaging sodium content the flood left behind.

The Big Haul

After flood waters recede, remove any large pieces of debris that may have washed into the yard, such as driftwood, tree branches and items from your neighbors' yards. These pieces not only wear away grass, but they also block sunlight while depositing extra salt on those sections of yard. Hand-remove the larger pieces, and use a rake to scrape away silt piles and other pieces of small debris.

Step by Step

Doing what you can to minimize soil compaction after a flood is crucial. Avoid all but the most necessary foot traffic, and aerate the lawn just after removing debris. With salt particles choking soil and grass roots, poking small holes in the ground will help open the lawn to the healing powers of sunlight, irrigation and other treatment. Use an aerating hand tool or spiked shoes for smaller areas, or an aerating machine for larger lawns.

Leaching the Lawn

Once you've removed debris and aerated the lawn, turn to your hose for re-flooding the yard -- but this time with fresh water. The fresh water leaches damaging salt content particles from the upper layer of soil and from grass blades. Use the strongest setting on your hose's nozzle attachment, and water the area frequently in the days following a flood. The sooner -- and more frequently -- you irrigate the lawn, the better chance you have of reducing salt damage.

Go With Gypsum

After you've irrigated the soil, turn to the garden amendment known as gypsum. This powdery material displaces sodium particles and replaces them with calcium. Unlike limestone, another high-calcium material, gypsum won't affect the pH of your soil. Apply a total of about 50 pounds of gypsum per 1,000 square feet of lawn, but break this application up into four or five treatments of 10 to 12 pounds at a time every few days. Hand-broadcasting over the grassy area is one method, or you may put the gypsum in a wheeled fertilizer-spreader. Water thoroughly after every application.

Watchful Waiting

Depending on what time of year a flood strikes, it's helpful to wait and see if grass rebounds on its own. Resist the understandable temptation to nourish the lawn to spur growth because most fertilizers are composed of salts that will only exacerbate the lawn's high sodium content. If the grass needs mowing, cut it an inch or two taller than you normally would, which will help build up root systems. The following season, if it's clear at least some of your grass won't be rebounding, you can then consider re-seeding or re-sodding.